Elastic drive



Dec. 4, 1928.

CZ. A. PARSONS ET AL ELASTIC DRIVE Filed March 24, 1927 inve n20?Patented Dec. 4, 1928.

' UNITED STATES PATENT OFFICE.

CHARLES ALGERNON PARSONS AND STANLEY SMITH COOK, OF NEWCASTLE-UPON-TYNE, ENGLAND; SAID COOK ASSIGNOR TO SAID PARSONS.

ELASTIC DRIVE.

Application filed March 24, 1927, Serial No.

This invention relates to elastic drives actingin conjunction withdevices for dampmg torsional oscillations.

When the torque to be transmitted varies considerably, as forexamplewhen starting or reversing with an internal-combustion or othervariable-torque engine as the source of power, such excessive torquemight be developed that it would be inconvenient or 1n 1-' practicableto provide for the whole of this torque to be transmitted by elasticityand damping in the elastic drives above nientioned.

The main object of the present inventionis to overcome suchdifficulties-and consists in the improved device hereinafter describedand more particularly pointed out in the claims. I

Referring to the accompanying drawings, which show one constructionalform of-the invent-ion by Way of example y- Figure 1 'isan elevationpartly in section, while Figure 2 is a cross-section on the line 2'2 ofFigure 1.

In carrying the invention into effect ac cording to one specific form, acircular box, a, open on one side is co-axially secured to the drivingshaft, 6, and in the outer portion of this box, i. e., that portion moreremote from the centre, a. series of damping plates, 0, d, arearranged-side by side, recesses, e, 6, being formed in the plates, 0, d,to receive the pads, f, f,-and springs, h, h, forgiving the drive thenecessary elasticlty.

The plates, 0, d, are arranged alternately, those marked 0 being splinedto or operatively associated in an equivalent manner as at c with theinner circumference of the box, a, and those marked d splined as at d tothe outer circumference of a second or inner of the elastic dampingplates, 0,-(Z,)' arranged alternately side by side, the plates marked nbeingsplined as at n to the inner circum ferenceof the second box, 7c,and-those marked the driven shaft.

177,967, and in Great Britain May 6, 1928. 4

0 splined as at 0 to the driven shaft or toy Annular covers, 8, t, areprovided respectively for the inner and outer boxes, a, k, to which theyare detachably secured by any suitable means, While each cover isprovided with sets of springs, s, t, and'screw or, other adjusters, 8 tby'which the force pressing the plates of each set together can be regulated. The annular cover, 5, of the inner box, is, is preferably mountedto rotate freely on the driven shaft While the annular cover of theouter box, if desired, may overlap the inner box to a certain extent asshown in Figure 1, so as to secure or assist in securing the latter inplace.

The driving shaft, b, is or may be provided with a coaxial extension,I), to serve on the one hand to centralize the main box and to provide abearing for the hollow driven shaft,

m, and on the other hand to receive a coaxial stud, c, or the like, thenut, o, of which presses a circular disc or plate, w, against aninternal shoulder on'the driven shaft and so holds the driving anddriven shafts in proper axial relation, for example during assembly ordismantling, without interfering with their freedom of relative angularmovement.

In the form of the invention particularly described, it will be seenthat the slipping coupling is compactly housed Within the el'asv ticcoupling but any other convenient construction may be adopted.

In order to secure the results desired the slipping coupling is designedto be operatively responsive to torques in excess of those safelytransmissible by the elastic damping coupling; for example, if theelastic coupling is capable of transmitting one-quarter the normaltorque by the damping friction alone and'two-anda-half'times the normaltorque by the damping friction and the action of the springs jointly,the slipping coupling may be designed to slip when transmitting saytwice the normal torque, which is the maximum permissible,

It Wll'lbfi obvious that the driving'and driven members may beinterchanged and that other variations in the details of constructionmay be made.

We claim:

1. In combination, a driving member and a driven member; anintermediateelement tlierebetween; an elastic drive and damping meanstherefor in parallel between one of said members and said intermediateelement, said drive being designed to transmit a certain working torque;and in series Wlth'Sfl-ld elastic drive and said damping means and inpower-transmitting relation between said intermediate element and theother. of said members a friction coupling capable of slipping anunlimited amount in response to the torques greater than said certainworking torque. a

2. The combination claimed in claim 1, in which said damping means andsaid friction coupling each comprise two sets of friction elements, theone set surrounding the other set. Y Y

3. The combination claimed in claim 1, in which said intermediateelement is rotatably mounted one of said members.

4. The combination claimed in claim 1, in which said dampmg means andsaid frlctlon containing both said damping means and said frictioncoupling; means for applying pressure laterally to said two sets offrictlon cle ments and detachable closing means on said intermediatemember and on said common I housing, said detachable closing meansserving as abutments for said pressure-applying means. 7

5. The combination claimed in claim- 1, in which said damping means andsaid friction coupling each comprise two sets of friction elements,thetwo sets of said damping means a being capable of only a limitedrelative move-' ment and the two sets of said friction coupling of anunlimited relative movement.-

In testimony whereof we have signed our names to this specification.

CHARLES ALGERNON PARSONS.

STANLEY SMITH COOK.

